i bought this sub new from digital designs a few months back for about $260 shipped. i have it in about 1.5cuft ported with 26sq" of port tuned to 40hz and running on a mtx 81000d. this sub replaced the 1508 that i came to love quite a bit actually. of course the 2510 is quite a bit louder than the 1508 and imo has better sound quality also. iam running the sub up and port up in an extended cab s-10 and this driver dishes out some good punishment to my ears:D.
eventually i will try it on a fusion nvam 2500d just to see how much power it will take. it eats the 1k from the 81000d easily and daily.
iam not shure on the 2510's x-max but i have seen 2" from it with no mechanical noises at all. the 2510 has no problems reaching over an octave below tuning while still having cone controll.
the best i got out of the 1508 on 1k was 140.4 on a tl on the dash with the windows half way open and the 2510 has that beat by far. my guess now would be near 142xx but will have to wait to get it metered untill my friend gets back from vacation.
i can tell you this, if your looking for a somewhat space-saving sub that can get insanely loud off moderate power while still sounding good then this is by far your best choice.
i will be doing an install in my wifes 93 olds cutlass using a dd3510 on the fusion nvam2500d. when its done i will make a review for it as well.
any questions, shoot me a pm and ill be glad to answer them.
will get some pics up later
-vic